The closest background art of the invention is disclosed in U.S. Pat. No. 4,585,885 in which a compound having the formula ##STR3## wherein R.sup.3 is an trialkylsiloxy group or an ether group, is oxidized with a percarboxylic acid to form a compound having the formula ##STR4## wherein R.sup.2 is as above.
This compound is then transformed into a compound having the formula ##STR5## wherein R.sup.3 is an alkylether or an hydroxy group.
This compound is then transformed into a Wittig compound which upon reaction with a compound having the formula ##STR6## will yield astaxanthin.